398 FLORIDA GEOLOGICAL SURVEY SIXTH ANNUAL REPORT. 



5. (Region 15, page 304.) Calcareous flatwoods, close to sea-level, about 

 a mile northwest of St. Mark's. Wakulla Co. Sept. 19, 1914. A blackish medi- 

 um sand, with almost no silt and clay, taken to a depth of 6 inches. Vegetation 

 Ambrosia sp., Flaveria sp., Chondrophora nudata, Pluchea bifrons, Cladium 

 effusum (saw-grass), Mesosphaerum radiatum, Monniera acuminata, Lippia sp., 

 Diclironiena colorata, Centella repaiida, Eupatorium mikaniodes, and a few 

 other peculiar herbs, with wire-grass and small scattered long-leaf pines. A 

 few earthworms found here, strange to say. 



6. (Region 17, page 314.) High pine land near Wade, Alachua Co. Depth 

 of sample 0-3 feet. Collected by Dr. E. H. Sellards. 



Analyses. 



I 23 4 5 6 



Moisture (H2O) 0.29 0.06 0.33 0.09 0.63 0.03 



Volatile matter 2.08 1.35 2.30 i.oo 3.07 0.52 



Nitrogen .115 -HO .120 .083 .145 .075 



Potash (K2O) .090 .029 .044 .033 .072 .033 



Lime (CaO) .145 -085 .090 .060 .190 .115 



Phosphoric acid (P2O5) .064 .044 .064 .044 .050 .072 



Iron and alumina (Fe203,Al203) — 3.83 0.33 1.38 1.14 1.53 0.60 

 Insoluble matter, 93.56 98.35 96.08 97.86 94.87 98.89 



Although these analyses do not all come out exactly as was expected, they 

 are not wholly inconsistent with what was already known of the vegetation and 

 agricultural resources of their respective regions. 



No. I is a pretty good average soil for northern Florida, and the statistics 

 given a few pages back for the region from which it comes (the West Florida 

 lime-sink or cypress pond region) are not far from the average for the whole 

 area. 



No. 2 has less of all soluble and volatile constituents. than any other in the 

 table, except that it exceeds in humus and the components thereof No. 4, which 

 is a subsoil, and No. 6, which is soil and subsoil mixed, and has a little more 

 lime than No. 4. It is not surprising therefore that it is uncultivated. 



The greatest surprise was in the case of Nos. 3 and 4, the soil and subsoil 

 so carefully selected from near Crawfordvllle, on a special trip made for the 

 purpose. By all accepted physical and chemical standards this should be a 

 rather poor soil ; but the vegetation and crops indicate decidedly otherwise. 

 Perhaps the main source of fertility lies in some constituent not considered in 

 these analyses ; or perhaps the soil has some peculiarity that enables plant roots 

 (especially in the case of trees, which have a life-time to do it in) to get more 

 out of it than the chemists' reagents do in a few days.* Another possibility is 

 that there is a more fertile stratum below the depth sounded (three "feet). 



♦Possibly a different method of analysis would give results more consistent 

 with the surface indications. Hilgard (Soils 343, 375) states that the A. O. A. C. 

 methods for soils extract less of some constituents, particularly potash, than his 

 acid-digestion method; and Mr. Heimburger used the A. O. A. C. methods for 

 fertilizers, which may differ in still other ways. And yet all of his analyses 

 having been made by the same method, ought to be strictly comparable with 

 each other, if not with those made by other methods; unless there is some 

 significant difference in the rate of reaction of soils of different texture to the 

 same reagents. 



